3,666 research outputs found
One-loop Electroweak and QCD corrections to vector boson scattering into top pairs and application to ILC
We calculate the electroweak and QCD corrections to W-W+ -> tt and ZZ -> tt.
We also consider the interplay of these corrections with the effect of
anomalous interactions that affect the massive weak bosons and the top. The
results at the VV level fusion are convoluted with the help of the effective
vector boson approximation to give predictions for a high energy e+e- collider.Comment: 19 pages, 27 figure
Anomalous Quartic and Couplings in Collision With Initial Beams and Final State Polarizations
The constraints on the anomalous quartic and
gauge boson couplings are investigated through the processes
and . Considering the
longitudinal and transverse polarization states of the final W or Z boson and
incoming beam polarizations we find 95% confidence level limits on the
anomalous coupling parameters and with an integrated luminosity
of 500 and =0.5, 1 TeV energies. Assuming the
couplings are independent of the
couplings we show that the longitudinal polarization state of the final gauge
boson improves the sensitivity to anomalous couplings by a factor of 2-3
depending on energy and coupling. An extra enhancement in sensitivity by a
factor of 1.3 comes from a set of initial beam polarizations
ILC Operating Scenarios
The ILC Technical Design Report documents the design for the construction of
a linear collider which can be operated at energies up to 500 GeV. This report
summarizes the outcome of a study of possible running scenarios, including a
realistic estimate of the real time accumulation of integrated luminosity based
on ramp-up and upgrade processes. The evolution of the physics outcomes is
emphasized, including running initially at 500 GeV, then at 350 GeV and 250
GeV. The running scenarios have been chosen to optimize the Higgs precision
measurements and top physics while searching for evidence for signals beyond
the standard model, including dark matter. In addition to the certain precision
physics on the Higgs and top that is the main focus of this study, there are
scientific motivations that indicate the possibility for discoveries of new
particles in the upcoming operations of the LHC or the early operation of the
ILC. Follow-up studies of such discoveries could alter the plan for the
centre-of-mass collision energy of the ILC and expand the scientific impact of
the ILC physics program. It is envisioned that a decision on a possible energy
upgrade would be taken near the end of the twenty year period considered in
this report
ANOMALOUS GAUGE BOSON INTERACTIONS
We discuss the direct measurement of the trilinear vector boson couplings in
present and future collider experiments. The major goals of such experiments
will be the confirmation of the Standard Model (SM) predictions and the search
for signals of new physics. We review our current theoretical understanding of
anomalous trilinear gauge boson self-interactions. If the energy scale of the
new physics is TeV, these low energy anomalous couplings are expected
to be no larger than . Constraints from high precision
measurements at LEP and low energy charged and neutral current processes are
critically reviewed.Comment: 53 pages with 17 embedded figures, LaTeX, uses axodraw.sty, figures
available on request. The complete paper, is available at
ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-871.ps.Z or
http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-871.ps.Z Summary
of the DPF Working Subgroup on Anomalous Gauge Boson Interactions of the DPF
Long Range Planning Stud
Recommended from our members
Anomalous gauge boson couplings
The measurement of anomalous gauge boson self couplings is reviewed for a variety of present and planned accelerators. Sensitivities are compared for these accelerators using models based on the effective Lagrangian approach. The sensitivities described here are for measurement of {open_quotes}generic{close_quotes} parameters {kappa}{sub V}, {lambda}{sub V}, etc., defined in the text. Pre-LHC measurements will not probe these coupling parameters to precision better than O(10{sup -1}). The LHC should be sensitive to better than O(10{sup -2}), while a future NLC should achieve sensitivity of O(10{sup -3}) to O(10{sup -4}) for center of mass energies ranging from 0.5 to 1.5 TeV
Study of V_LV_L to t tbar at the ILC Including O(alpha_s) QCD Corrections
In the event that the Higgs mass is large or that the electroweak
interactions are strongly interacting at high energy, top quark couplings to
longitudinal components of the weak gauge bosons could offer important clues to
the underlying dynamics. It has been suggested that precision measurements of
W_L W_L to t tbar and Z_L Z_L to t tbar might provide hints of new physics. In
this paper we present results of O(alpha_s) QCD corrections to V_LV_L to t tbar
scattering at the ILC. We find that corrections to cross sections can be as
large as 30% and must be accounted for in any precision measurement of VV to t
tbar.Comment: 8 pages, 8 figures, Minor changes in wording. uses Revtex
Top-BESS model and its phenomenology
We introduce the top-BESS model which is the effective description of the
strong electroweak symmetry breaking with a single new SU(2)_L+R triplet vector
resonance. The model is a modification of the BESS model in the fermion sector.
The triplet couples to the third generation of quarks only. This approach
reflects a possible extraordinary role of the top quark in the mechanism of
electroweak symmetry breaking. The low-energy limits on the model parameters
found provide hope for finding sizable signals in the LHC Drell-Yan processes
as well as in the s-channel production processes at the ILC. However, there are
regions of the model parameter space where the interplay of the direct and
indirect fermion couplings can hide the resonance peak in a scattering process
even though the resonance exists and couples directly to top and bottom quarks.Comment: published in Physical Review D, minor changes in text, 21 pages, 37
figure
Inclusive One- and Two-Jet Cross sections in Reactions at Colliders
We have calculated inclusive one-- and two--jet production in photon--photon
collisions superimposing direct, single resolved and double resolved cross
sections for center of mass energies of the LEP1, LEP2 and NLC range. The
direct and single resolved cross sections are calculated up to
next--to--leading order. The double resolved two--jet cross section is
calculated only in LO with a factor estimated from the NLO one--jet cross
section. Various differential cross sections as functions of transverse momenta
and rapidities of the jets are evaluated.Comment: 25 pages, latex, 15 figures appended as uuencoded fil
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